A hemispherical bowl has 3.5 cm radius. It is to be painted

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A hemispherical bowl has 3.5 cm radius. It is to be painted inside as well as outside. The cost of painting it at the rate of Rs. 5 per 10 sq. cm will be:

1. Rs. 77
2. Rs. 100
3. Rs. 175
4. Rs. 50

Correct Option: A

Inner and outer surface areas of the bowl = 4πr²

= 4 ×	22	× 3.5 × 3.5 = 154 sq. cm.
	7

∴ Cost of painting = 154 ×	5	= Rs. 77
	10